In computer science, a reference is a value that enables a program to indirectly access a particular datum, such as a variable or a record, in the computer's memory or in some other storage device. The reference is said to refer to the datum, and accessing the datum is called dereferencing the reference.
A reference is distinct from the data itself. Typically, a reference is the physical address of where the data is stored in memory or in the storage device. For this reason, a reference is often called a pointer or address, and is said to point to the data. However a reference may also be the offset (difference) between the datum's address and some fixed "base" address, or an index into an array.
References are widely used in programming, especially to efficiently pass large or mutable data as arguments to procedures, or to share such data among various uses. In particular, a reference may point to a variable or record that contains references to other data. This idea is the basis of indirect addressing and of many linked data structures, such as linked lists.
References increase flexibility in where objects can be stored, how they are allocated, and how they are passed between areas of code. As long as one can access a reference to the data, one can access the data through it, and the data itself need not be moved. They also make sharing of data between different code areas easier; each keeps a reference to it.
The mechanism of references, if varying in implementation, is a fundamental programming language feature common to nearly all modern programming languages. Even some languages that support no direct use of references have some internal or implicit use. For example, the call by reference calling convention can be implemented with either explicit or implicit use of references.
5.3.2 Construct algorithms that use reference mechanisms.
5.3.3 Discuss the features and appropriate usage of single, double and
circular linked lists.
5.3.4 Outline and illustrate how links operate logically.
5.3.5 Trace algorithms to implement linked lists.
5.3.6 Construct algorithms to implement linked lists.
5.3.1 Define object reference.
Reference
In computer science, a reference is a value that enables a program to indirectly access a particular datum, such as a variable or a record, in the computer's memory or in some other storage device. The reference is said to refer to the datum, and accessing the datum is called dereferencing the reference.
A reference is distinct from the data itself. Typically, a reference is the physical address of where the data is stored in memory or in the storage device. For this reason, a reference is often called a pointer or address, and is said to point to the data. However a reference may also be the offset (difference) between the datum's address and some fixed "base" address, or an index into an array.
References are widely used in programming, especially to efficiently pass large or mutable data as arguments to procedures, or to share such data among various uses. In particular, a reference may point to a variable or record that contains references to other data. This idea is the basis of indirect addressing and of many linked data structures, such as linked lists.
References increase flexibility in where objects can be stored, how they are allocated, and how they are passed between areas of code. As long as one can access a reference to the data, one can access the data through it, and the data itself need not be moved. They also make sharing of data between different code areas easier; each keeps a reference to it.
The mechanism of references, if varying in implementation, is a fundamental programming language feature common to nearly all modern programming languages. Even some languages that support no direct use of references have some internal or implicit use. For example, the call by reference calling convention can be implemented with either explicit or implicit use of references.
5.3.2 Construct algorithms that use reference mechanisms.
5.3.3 Discuss the features and appropriate usage of single, double and
circular linked lists.
5.3.4 Outline and illustrate how links operate logically.
5.3.5 Trace algorithms to implement linked lists.
5.3.6 Construct algorithms to implement linked lists.